Sudden lost of the sp mixer outputs while playing

Hi, it’s about two or three weeks than while I’m playing In ableton with sp plugin, suddenly It lost the sp mixer output.
I mean the inputs are still comin in, like you can see in the picture attached, but aren’t flowing out from the sp mixer outs channels.
If I close and reopen ableton it works again but, after let’s say 20 min it losts again the outputs.

Someone has experienced the same issue?

Update on the issue.
When happens, if I press stop and then play it works again.